Ireland is not a British Isle/Island. This is an outdated Imperialistic and Possesive term that is not recognised by the Irish Government nor by the Majority of Irish people living in Ireland.
Ancient Roman Pliny called Hibernia (Ireland) one of the 'Britanniae' islands. 'Britanniae' being the plural of 'Britannia''. Not a possession of the people of 'Albion', the larger of the 'Britanniae'. Simply a member of a group of islands. In the way that Coll & Tiree are 2 of the Hebrides islands, not a possession of the largest Hebridean island Lewis. So yes Ireland is indeed a British isle and referred to as such for centuries prior to Medieval imperial Britain. Following the Romans withdrawal from Albion, the people of Hibernia began to extend power and dominion over parts of Albion, taking slaves from there. The definition of imperialism and long before medieval Ireland became an imperial possession of England.